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| #5432 (Received by flhurricane at: 4:56 AM 17.Aug.2004) TCDAT4 HURRICANE DANIELLE DISCUSSION NUMBER 16 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 5 AM EDT TUE AUG 17 2004 THE APPEARANCE OF THE EYE OF DANIELLE HAS BEEN INTERMITTENT. HOWEVER ...WHEN THE EYE HAS BEEN PRESENT...ODT INTENSITIES HAVE BEEN AS HIGH AS T5.1...OR 92 KT. THE SUBJECTIVE DVORAK T-NUMBERS FROM THE THREE SATELLITE AGENCIES HAVE COME DOWN SLIGHTLY...BUT STILL INDICATE AT LEAST 85 KT. GIVEN THE HIGHER ODT VALUES AND THE COLD TOPS STILL PRESENT IN THE EYWALL...THE INITIAL INTENSITY WILL BE HELD AT 90 KT FOR THIS ADVISORY. OUTFLOW REMAINS GOOD IN ALL QUADRANTS. THE INITIAL MOTION IS NOW 335/14. THE SATELLITE FIX POSITIONS HAVE BEEN COMING IN ON TRACK. DANIELLE IS EXPECTED TO GRADUALLY TURN NORTHWARD IN THE NEXT 12 TO 24 HOURS AS THE CYCLONE IS INFLUENCED BY THE SOUTHERLY FLOW ON THE EAST SIDE OF A LARGE MID- TO UPPER-LEVEL LOW LOCATED ABOUT 450 NMI NORTHWEST OF THE HURRICANE. AFTER THAT...DANEILLE IS FORECAST BY ALL OF THE MODELS TO GRADUALLY ROUND THE TOP OF THE MID-LEVEL SUBTROPICAL RIDGE LOCATED ALONG 25N LATITUDE. AFTER RECURVATURE BEGINS IN 48-60H...DANIELLE IS EXPECTED TO TURN EAST-NORTHEASTWARD AND MOVE TO NEAR THE AZORES ISLANDS BY DAY 5. THE OFFICIAL FORECAST TRACK IS JUST AN UPDATE AND EXTENSION OF THE PREVIOUS TRACK AND IS CLOSE TO THE NHC MODEL CONSENSUS. THE SHIPS INTENSITY MODEL CURRENTLY SHOWS 34 KT OF SOUTHWESTERLY SHEAR ACROSS DANIELLE. USUALLY SUCH STRONG SHEAR CONDITIONS WOULD HAVE DISRUPTED THE CONVECTIVE PATTERN ENOUGH TO CAUSE SIGNIFICANT WEAKENING TO OCCUR...BUT THIS HAS NOT BEEN THE CASE. GIVEN THAT THE SHIPS MODEL GRADUALLY WEAKENS THE SHEAR WITH TIME AND THAT AT LEAST 27C SSTS ARE AHEAD OF THE HURRICANE THROUGH 60H...THE INTENSITY OF DANIELLE IS ONLY DECREASED SLOWLY THROUGHOUT THE FORECAST PERIOD... AND IS GENERALLY HIGHER THAN SHIPS MODEL FORECASTS. BY 120H...IT IS POSSIBLE THAT DANIELLE COULD MERGE WITH A FRONTAL SYSTEM SOUTHWEST OF THE AZORES AND BECOME AN EXTRATROPICAL GALE AREA IN THE ISLANDS. FORECASTER STEWART FORECAST POSITIONS AND MAX WINDS INITIAL 17/0900Z 22.3N 39.9W 90 KT 12HR VT 17/1800Z 24.1N 40.6W 80 KT 24HR VT 18/0600Z 26.4N 41.1W 75 KT 36HR VT 18/1800Z 28.6N 41.1W 70 KT 48HR VT 19/0600Z 30.5N 40.7W 65 KT 72HR VT 20/0600Z 34.0N 38.5W 60 KT 96HR VT 21/0600Z 36.5N 34.0W 50 KT 120HR VT 22/0600Z 39.5N 28.0W 40 KT...EXTRATROPICAL |
